Fitness Trackers Are Long on Hype, Short on Credibility

Photo: Ariel Zambelich/Wired

We are awash in personal data trackers. There are wristbands, headbands, watches, smart scales, helmets and even forks to help us track our weight, heart rate, blood pressure and glucose level while logging how far we walk and how many calories we burn. All this information is supposed to give us behavior-morphing insights into our personal health habits.

Trouble is, no one can say for sure that any of it makes us healthier. Oh sure, these gadgets might get us psyched up to exercise, and they might encourage us to take the stairs instead of the elevator, but there has not yet been any scientific exploration of whether fitness gadgets, like the Fitbit Flex or Withings Smart Activity Monitor, actually work like they should.

“The durability of the effect is still in question,” said Dr. Eric Topol, the director of the Scripps Translational Science Institute. “We don’t have randomized [clinical] trials showing improved outcomes or durability in influencing behavior.”

You wouldn’t know that walking through the South Hall of the Las Vegas Convention Center during CES, where more than 220 companies showed off their digital health gadgets. They all used pictures of youthful, happy, svelte people lacing up running shoes, eating salads and playing outdoors. Their booths were filled with attractive, fit gals and guys.

The message is clear: These devices will help improve your health and physique.

But so far there aren’t many studies or trials testing the effectiveness of activity trackers or health monitors at getting us to move more and eat better foods or whether digital sensors are any better than old-school approaches like Weight Watchers.

Many of these devices have been developed by startups or Kickstarter campaigns and simply don’t have the deep pockets necessary to finance expensive clinical trials, says Topol.

Some researchers, Topol included, are following the wave of health technology with studies testing how activity monitors and other digital health sensors influence outcomes for chronic illnesses like cardiac disease and diabetes.

Other scientists at the University of California, San Francisco; Mayo Clinic; Massachusetts General Hospital; and Aurora Health Care are conducting trials to determine how digital data trackers affect activity levels, obesity and dietary intake in various populations. Some of these trials are just now recruiting patients or recently finished collecting data.

Dr. Anne Thorndike, a researcher at Harvard Medical School, is wrapping up a study of Fitbit’s effect on activity levels among medical residents. She couldn’t share all her findings because she’s still submitting her study for publication, but said there was some fatigue over the course of her 12-week study, suggesting the motivating effect of information, badges and notifications might be short-lived. That’s to be expected. As with any new toy or gadget, the novelty wears off.

A 2007 study in the Journal of the American Medical Association found that using pedometers, activity monitors and step counters was associated with being more physically active and having a lower body mass index and blood pressure. But the authors note that “whether these changes are durable over the long term is undetermined.”

The key to prolonging people’s engagement with their trackers might be to harness the social networking features built into the devices. Some research has shown social networks can impact health outcomes for patients with migraine, obesity and ALS, but whether that will translate to sensor-based social networks remains to be seen.

At this point, the connection between sensor-collected data and a patient’s official (electronic) health record also is not well defined. There’s no simple interface to upload data collected by biometric sensors into medical health records short of printing out your data, scanning it and converting it into a PDF you can send to your doctor.

That might become more of an issue as personal data trackers mature from pedometers pimped out with great user interfaces into hardware that’s being added to mobile devices to gather data typically collected by physicians, like electrocardiograms, galvanic skin response and blood oxygenation and glucose levels, says Topol. And that democratization of health care is what he sees as the biggest benefit of these devices. He predicts 2013 will see more “medical wearables,” which will make studying conditions like sleep apnea more comfortable and less expensive for patients.

The next step is the commercialization of sensors floating around in our bloodstreams or implanted in our skin, teeth or brains.

As these medical sensors become more pervasive, companies also will have to be conscious of how they market their products. For example, the Masimo iSpO2 pulse oximeter is approved for consumers to measure their own blood oxygen levels and pulse rates using the similar technology used in hospitals. But because it’s not approved for medical use, doctors can’t use it or have their patients use products like this until they are approved by the Food and Drug Administration. AliveCor, which makes a portable electrocardiogram built into an iPhone case, faced similar issues until it was approved by the FDA in December.

“It’s like the wild, wild West,” said Dr. Atul Butte of the Stanford School of Medicine, who just started using a Fitbit and an Aria Scale. “For a drug company, there’s such a burden to show how [their product] works better. A gadget maker is … not required to show that data and that’s kind of unfair.”

“Probably, like most gadgets, these devices help those folks on the borderline, [those] ready to make behavioral changes and looking for something to tip them into healthy behaviors,” he added.

After a few days of using his own trackers, Butte admits he’s “already making changes like switching from lattes to more espressos.”